Method for continuous lautering



Apnl 1, 1969 0.0. scHAus METHOD FOR CONTINUOUS LAUTERING Filed April 5.1965 FIG. I

FIG. 2

l N VEN TOR.

8 m N Wm O A D N A m 0 Ww United States Patent "ice 3,436,226 METHOD FOR'CONTINUOUS LAUTERING Orland O. Schaus, Toronto, Ontario, Canada,assignor to Canadian Breweries Limited, Toronto, Ontario, Canada FiledApr. 5, 1965, Ser. No. 445,384 Int. Cl. C12c 7/14, 7/16; B01d 33/24 US.C]. 99-52 2 Claims ABSTRACT OF THE DISCLOSURE This invention relates toapparatus for and a method of continuously lautering brewers mash.

The lautering of brewers mash on a continuous, as distinct from a batchbasis, has for some years been a problem without satisfactory answer.During the past ten years new brewing techniques in which the wort isfermented on a continuous basis have been developed. The full benefit ofthese continuous fermenting techniques from a production point of Viewcan only be realized if they are combined with a continuous mashing andlautering technique. Continuous lautering has to date been difficult todo. At least two approaches have been tried, each with less thanentirely satisfactory results.

Centrifugal separators have been used to separate the spent grains fromthe extracting liquid of the mash. Separators of this type are costly toinstall difficult to maintain because of high rotational speeds andsubject to breakdown, with the result that the continuity of the processis often broken. Moreover, they do not give complete separation ofsolids and liquid.

In a different method of the prior art the mash is spread on the upperflight of a moving perforate belt conveyor, the perforations of whichare of suflicient size to support the spent grains in a filter bed butlarge enough to let the extracting liquid of the mash pass therethrough.The method has been used with some success, but difiiculty is oftenencountered as the filter bed of spent grains through which theextracting liquor passes cracks and loses its filtering value. Crackingis caused by movement of the flexible conveyor belt or by frictionbetween the flexible belt and its support structure. Moreover, it willalso be apparent that only the upper flight of the conveyor can be usedfor filtering purposes so that in effect only one-half of the filtersurface provided is in actual use at any one time. The equipment isrelatively bulky because the path of the conveyor belt must be in asingle straight line.

It is therefore an object of this invention to provide a filteringmethod and apparatus for brewers mash that is capable of supporting themash in .a filter bed which eliminates the danger of cracking the filterbed. It is also an object of the invention to provide a method andapparatus for lautering brewers mash that makes a more efiicientutilization of the filtering surface.

It is a still further object of the invention to provide apparatus andmethod for lautering brewers mash that is compact.

With these and other objects in view, lautering apparatus for brewersmash according to this invention generally comprises a foraminous rigidtable, table mounting means for rotatably mounting the table about anaxis 3,436,226 Patented Apr. 1, 1969 substantially at right angles tothe plane thereof, the table having foraminations of a size to screenthe grains from the mash in use and let the extractnig liquid passtherethrough. Means are also provided for rotating the table and fordepositing brewers mash on the table at a distance from the centre ofrotation thereof, whereby the mash is spread on the table in a filterbed of annular configuration as the table is rotated in use by the tablerotating means. Sweeping means for sweeping the filter bed of mash fromthe table are provided and collecting means are provided under the tablefor collecting the extracting liquid from the mash. The apparatus andthe method of the invention will be clearly understood after referenceto the following detailed specification read in conjunction with thedrawings.

In the drawings:

FIGURE 1 is a perspective view of lautering apparatus according to thisinvention, and

FIGURE 2 is a sectional view along the line 22 of FIGURE 1.

Referring to the drawings, the apparatus for lautering brewers mashthere illustrated comprises a foraminous rigid table 10 of annularconfiguration supported at its centre by the tubular pillar 12, which isin turn rotatably mounted on the tubular floor supported base 14 bymeans of bearings contained in the illustrated exterior flangesillustrated at 16. Detail of the bearing arrangement is not illustratedin the drawings since it is of standard design.

The table 10 is made of steel and has an exterior circumferential fence18 at its outer edge and a resilient seal 20 at its inner edge whichengages with the plough sweeping structure 22 that is in turn carried bythe feed hopper 24. Feed hopper 24 is mounted rigidly with respect tothe floor but independently of the table to overlie the table asillustrated and will be referred to in more detail later.

A motor 2-6 connects through a transmission, generally indicated by thenumeral 28, with the pinion gear 30 to rotate the table through the gear32, which is in turn carried by the support pillar 12. It will be notedthat support pillar 12 connects with the table at its inner edge bymeans of a circumferentially extending moulding 36 so that operation ofthe motor to rotate gear 30 will in turn rotate the table past the abovementioned rigidly mounted feed hopper 24.

Underneath the table there is mounted two annular wort tanks for thepurpose of collecting the extracting liquor or wort from the mash inuse. Means including pipes 40 and pump 42 and spray nozzles 43 areprovided for returning wort from the tank 44 to a bed of mash overlyingthe table 10. Piping means 48 are provided for conducting clear wortcollected in the tank 46 away therefrom. Rakes 50 are provided forbreaking the top crust of a bed of mash on the table to facilitatebetter drainage and inlet pipes and sparging nozzles 52 are provided foradding sparge water to a bed of mash on the table.

To lauter mash with the apparatus described herein the mash is fed ontothe table 10 through the rigidly mounted feed hopper 24 as the table isrotated thereunder by means of the motor 26 and its gear train abovedescribed. It will be noted that the mash feed hopper extends radiallyacross the annular configuration of the table whereby mash is formed ina bed concentric with the centre of rotation of the table as the tablerotates.

As described above, the table has foraminations therein of a size thatwill screen the grains from the mash and let the extracting liquor passtherethrough. When the mash is initially deposited on the table theliquor tends to run through rather freely and is collected in the firsttank 44. This liquor is cloudy because it has not been filtered througha bed of settled grains from mash. It therefore is returned to the bedfor recirculation by 3 means of the pump 42, pipe 40 and theirassociated spray heads.

As the grains settle on the table 10 they tend to form themselves into abed that acts as a filter for the extracting liquor. Thus, once thefilter bed is formed, the extracting liquor passing therethrough isfiltered by the filtering action of the grains. This liquor is clearwort and enters the Wort collecting tank 46. It will be apparent thatthe location of the cloudy Wort return nozzles 43 should be sutficientlyfar from the feed hopper 24 to enable the bed of grain formed on thetable 10 to settle sufiiciently to form itself into a filter.

As the table moves in a counter-clockwise direction, filtering of theextractant takes place as the extractant passes through the grains. Thetop crust of the bed may tend to become hard and less permeable than themash and to overcome this, rakes 50 are provided which break the topinch or so of the annular bed of grains from the mash and permit anycontained moisture to pass through the filter bed.

In order to remove as much as possible of the valuable sugars from thegrains on the table, a s'parge line 52 is provided which sprays warmwater onto the bed of grains as it passes thereunder. The water filtersthrough the bed and is collected by the wort collecting tank 46.

After the grains have travelled on the table a sufiicient time to permitmost of the extracting liquor of the mash to pass therefrom and throughthe rigid screen 10, they encounter the plough 23 which extends radiallyacross the support table 10 and is arranged to sweep the grains from thetable into the tubular chute provided by the interior of the tablesupport 12 and the base 14. From the bottom of the base the spent grainsare taken to waste.

A feature of the invention is the rigidity of the table 10 upon whichthe mash is spread. This table is able to support the overlying bed veryfirmly and substantially eliminates any possibility of cracking of thefilter bed by reason of yielding f the filter bed or frictional contactof the bed with another structure. It will be apparent that the deviceis compact and that substantially all of the foraminous surface supportsgrain.

A table having an outside diameter of about 12 feet with an open chutediameter for the spent grains of about four feet are practical sizes butit will be appreciated that these things can be varied. The speed ofrotation varies with the height of the bed of grains and the degree offiltering sought but with the grains arranged about 12 inches deep thespeed of rotation should be arranged such that the grain takes about 1.5hours to travel from the hopper 24 to the discharge gate 23.

Modifications which affect these design features can be incorporated andWill be apparent to those skilled in the art.

For example, slight vacuum can be applied to the under-side of thefilter bed to accelerate drain off. This would permit a faster operationof the table for equivalent filtering effect.

Other modifications based on known filter practice will be apparent tothose skilled in the art and it is not intended that the foregoingdescription be read in a limiting sense.

What I claim as my invention is:

1. A method of continuously lautering brewers mash comprising the stepsof continuously depositing brewers mash on a bed having an annularconfiguration on a rigid foraminous table by continuously rotating thetable, so that the bed of mash formed Will not crack, said table havingforaminations of a size to screen the grains from said mash and let theextracting liquid pass therethrough; said mash being deposited at a rateand said table continuously rotating at a rate to form said bed with adepth that acts as a filter for said extracting liquid, continuouslyremoving grains from said table after they have been thereon for apredetermined time, said predetermined time being suflicient to permitmost of the extracting liquor of said mash to pass therefrom and throughsaid screen, and collecting said extracting liquor after it fallsthrough said table.

2. A method of continuously lautering brewers mash as claimed in claim 1in which at least some of said extracting liquor that falls through saidtable is returned to the top of said bed for recirculation through saidbed.

References Cited UNITED STATES PATENTS 2,961,316 11/1960 Cook et al.9952 3,161,522 12/1964 Compton 9952 FOREIGN PATENTS 929,835 9/1963 GreatBritain.

A. LOUIS MONACELL, Primary Examiner.

NORMAN ROSKIN, Assistant Examiner.

U.S. Cl. X.R. 99-278

